Water quality monitoring is necessary for numerous applications, especially if the water is to be used for human consumption. One analysis technique conventionally used for water quality monitoring is ion chromatography. This technique is often utilized for the detection of the chemical groups: monovalent and divalent cations, halides, transition metals, organic acids, and low molecular weight alcohols and amines (hereafter referred to as chemical groups).
The analysis requires a packed sorbent column capable of separating compounds in solution and an eluant mobile phase (hereafter referred to as eluant) to liberate the absorbed chemical compounds from the sorbent column and carry them into the detector. The eluant, generally aqueous salt solutions of 0.5 to 2.0 mM (millimolar) concentrations, is typically prepared manually as needed for analysis.
In applications where the eluant can not be readily supplied, such as in long term submarine or space missions, it is necessary to prepare the eluant, in advance, for the entire mission. Typically, approximately 200 cc (cubic centimeters) of eluant is required for each chemical group analysis. On a space mission, for example, there may be two complete chemical group analyses planned per day with six chemical groups to be analyzed. As a result, a minimum of approximately 2.5 liters (L) of eluant must be available, in storage, for each day of the mission. A 90 day mission would require approximately 225 L of eluant to be stored which is a severe expendable penalty. Additional concerns, including storage constraints, launch and resupply costs, size, weight, expendable use, and recyclability must also be taken into consideration in these applications.
Since weight and size constraints among others, are very important, what is needed in the art is an apparatus and process for efficiently preparing eluant from concentrate and reclaiming the water used in the preparation for subsequent use.